Big fat galaxy cluster discovered

The biggest and hottest galaxy cluster in the distant universe has been discovered. The huge galaxy cluster, ACT-CL J0102-4915, more than seven billion light years away, has been dubbed El Gordo (The Fat One) by Chilean researchers who located it.

It was discovered in Chile at the North American Space Agency's (NASA) Chandra X-ray Observatory and the Atacama Cosmology Telescope (ATC).

Study leader, Felipe Menanteau, of Rutgers University, in New Brunswick, New Jersey, USA, says, "This cluster is the most massive, the hottest, and gives off the most X-rays of any known cluster at this distance or beyond."

Galaxy clusters are created when smaller groups of galaxies join and are held by gravity - the biggest objects to do so. Their creation is reliant on dark energy and dark matter. Dark energy is a theoretical form emitting negative pressure that leads to the increasing expansion of the universe. Dark matter is believed to exist because of its gravitational effects, even though any light it absorbs cannot be detected.

Researcher, Jack Hughes, also of Rutgers University, says, "Gigantic galaxy clusters like this are just what we were aiming to find. We want to see if we understand how these extreme objects form using the best models of cosmology that are currently available."

The fact that El Gordo is so far away means it can be seen at a young age. It was found because of the Sunyaev-Zeldovich effect, where high-energy cluster electrons distort the cosmic microwave background radiation when colliding with low-energy photons.

X-ray data from Chanra and the aptly-named 8-metre Very Large Telescope in Chile, reveal that El Gordo is the scene of a high-speed collision between two galaxy clusters, similar to the Bullet Cluster, which is three billion light years away from Earth.

Cristobal Sifon, from Pontificia Universidad de Catolica de Chile (PUC), in Santiago, says, "This is the first time we've found a system like the Bullet Cluster at such a large distance. It's like the expression says: if you want to understand where you're going, you have to know where you've been."

The findings of the team are being revealed in more detail at the 219th meeting of the American Astronomical Society, in Austin, Texas, USA, and will be published in The Astrophysical Journal.

Sponsors

Recent News

Quantification of the iconic polar bears fate is important as the ice melts ever more readily. Here is the real story we can expect as we struggle to conserve all the species we can, while the world warms inexorably.

One great devil ray species (Mobula mobular) was doing well in the Mediterranean Sea last year, but it is still classed as endangered, whether in Gaza or migrating to the Tuscan Sea. As it isnt a food item, this probably saves it from the fate of its smaller relatives. They are disappearing fast, and there has been little effort at conservation.

When we lose so many animals and plants from South America, often as soon as they are discovered as new species. It is consoling to discover such an animal that seems to be looking after itself, in secondary forest, and with hopes of recovery from population loss. Of course, some smart new conservation effort may be required in the form of forest regeneration and afforestation ----- !

When dolphins are 'rescued' in various countries, the car given seems to be ill-considered. We are simply looking at the success rate which is reported to be low, in most places. They could even end up in commercial aquarium shows, but they certainly rarely make it back to the sea.